This invention relates generally to semiconductor device manufacturing and more specifically to a method of preventing clogs in an exhaust line of a baking chamber for use in semiconductor manufacture.
In semiconductor manufacture, photolithography is a process that produces circuit patterns on a surface of a wafer using light-sensitive photoresist material and controlled exposure to light. Applying and developing the photoresist material involves several heating steps that are performed within an enclosed chamber of a wafer track system. The wafer is heated on a hot plate and air flows through the chamber to ensure film uniformity and to exhaust out the evaporated solvent coming from the photoresist.
A problem with heating the wafer within the enclosed chamber is that a temperature difference between the hot plate and the chamber cover causes condensation of the evaporated solvent and thus, produces small powdery particles that attach to and clog up the exhaust line of the chamber cover. Maintaining and cleaning the exhaust line is time-consuming which results in a long down time of the chamber. What is needed is a simple and cost-effective method for preventing clogs in the exhaust line to reduce the down time of the chamber and to secure a contamination-free environment for the chamber.